Carburetor fuel supply system



`Iuly 14, 1931. R. F. BRAcKE CARBURETOR FUEL SUPPLY SYSTEM 2 lsheets-:sheet 1 Filed OGI.. 14, 1926 5 Z f w l 9 m Wfl/1,2# .d nv a H11 w.. 1| me l K u M I1 1 1 1 m l MW M 9 2 n V 5 ,j l( 2 6 l QJ f ,a

July 14, 1931. R. F. BRACKE CARBURETOR FUEL SUPPLY SYSTEM 2 Sheets-Sheet 2 Filed Oct. 14, 1926 @Warne 12 Patented July 14, 1931- UNITED sTATs PATENT ori-"ICE ROBERT F. `BRACXE, F CHICAGO, ILLINOIS, ASSIGNOR T0 CURTIS B. CAMP, f

TRUSTEE, OF CHICAGO, ILLINOIS oAmsnE'ron FUEL SUPPLY srrszrmm:`

Appumion mea october 14, 192e. serial m. 141,489.

My invention relates generally to carburetors and more particularly to devices of this class in which the vacuum in the induction assage is utilized to draw the liqu1d l fuelA rom a low level supply tank.

It is an objectof my invention to provide an im roved .system and means for supplying fluid fuel to a carburetor from a low level supply tank. U Y

A further object of my invention 1s to provide an im roved carburetor and float chamber in which the degree of vacuum in the float chamber is automatically regulated.

Other objects will appear from the following description,.reference being had to the accompanying drawings, in which Figure 1 is a `central vertical sectional view of my improved carburetor and float lchamber, or'auxlliary tank.

Figure 2 is .a dlagrammatical sectional view of an automobile showing the relative location of the parts of my carburetor sysf tem.

Figure 3 is a central vertical sectional view of a modified form of my invention.

Referring to Figure 2, it will be noticed that the supply tank 4 is connected by means, of a tube 5 withthe float chamber 6, and that this chamber lies at a level below that of the bottom of the tank.A The oat chamber' 6 is connected to the carburetor 7 by means of two pipes 8 and 9, as will hereinafter be more fully described. As is usual the carburetor is secured to the intake mani,

fold b means of bolts passing through a flange 7o: of the carburetor.

Referring more particularly to Figure 1, a brief general description of the carburetor willbe given. An -induction assage 117is formed in the carburetor body the ow of the charge from this passage being regulated by a throttle Avalve 12. 4Air is admitted to this induction --passage from the air inlet .pipe 13, the opening of which may be conf trolled by the `butterfly -choke valve 14.

When. the air pressure in the induction passage 11 drops below atmospheric pressure,

an air admission valve 15 which rests on a seat 16 is raisedl from its seat to permit the passage of airv from the air inlet pipe into the induction passage, The air valve 15 is normally retained upon its seat by the compression coilv spring 17 which rests in a dashpotpiston 18 which isintegral with the stein of the valve 15.` The effective pressure of the spring 17 maybe varied by rotatably adjusting the regulating nut 19- to increase or decrease the amount of compression in the spring 21 which is positioned so as to partially counteract the effect of the s ring 17. The dashpot arrangement prevents uttering Aof the valve 15.

.the float chamber 26 and terminates near its bottom while the tube 9 terminates at the top of the chamber. A fuel connection 27 is screwed into the side of the float chamber body 6 and leads into an annular chamber l28 surrounding the' plug 29 which is threaded into the body. The plug 29 is axially plurality of ducts 25 lead bored at 31 and has a plurallty of openings communicating with the chamber 28. A screen-strainer 32 surrounds the plug 29 to prevent the entrance of dirt and other foreign matter into ythe float chamber. The fuel maypass from the bore 31 through a hori-. zontalpassage 33 which leads to'a Valve seat 34.' A blunt needle valve 35, retained and guided in the oat chamber by means of a socket cap 36 threaded into thel top of the body registers with the seat 34 and is adapted to control the flow of fuel from the pas l A sage 33 to the iioat chamber 26. Pivotally mounted on lugs 37 dependingfrom the top of the body 6, are a air of Weighted levers 38,:,the outer ends o which are adapted to rest on the top of the hollow metallic ioat 39 which is guided by the lstem 35. The in- I ner ends of these levers, as is usual, lit between'a pair of collars 41 formed on the stem of` the needle valve 85. It will thus be apparent that the opening ofthe valve 35 is controlled by the position of the float. A guiding lug 42 formed integral with the bottom of the body 6 forms acentering support. for the lower end of thestem of the valve 35. An air check valve comprising a seat 43 screwed in the top of the body 6 and aspring-prssed ball closure 44 prevent the formationpf an excessive vacuum within the float chamber.Y The pressure of the ball upon its seat may be adjusted by rotation of the seat, and thus the maximum vacuum in the ioat chamber may be regulated.

It has been found that the vacuum in the induction passage 11 is suificient to draw the fuel from the supply tank 4 under all ordinary circumstances even when the car is going up a steep hill. Thus the reduction of pressure in the pipe 9 is sufficient to continually maintain the required level of gasoline or other fuel in the float chamber. This I is of great importance since the amount of fuel drawn through the Venturi nozzle is in part dependent upon the level of the fuel and the pressure in the float chamber. By my improved device the pressurein the fioat chamber is maintained at or above a predetermined minimum pressure which maybe adjusted by rotation of the seat 43'of'the air check valve. f While, as has been said, the suction in the inductionpassage is suflicient to draw `the fuel from the supply tank, it is not very great under normal operating conditions, so that great fluctuations of the pressure in the float chamber are improbable, thus insuring a constant pressure source of fuel supply for the carburetor.

In Figure 3 I have shown a modified con- Y struction in which'the suction pipe 9 is connected to the induction passage through a.

duct 46 in which a perforated cylindrical cap 47 is ixed,'the perforations being designated at 47 This cap by reason of the perforations acts as a Calibrating means to prol duce the proper suction in the float chamber.

The cap 47 is -positioned adjacent the head of the valve 15 and as the val-ve rises under the inuence of induction chamber depression, the head of the same will shut oft1 certain of the perforations 47 'longitudinally spaced in the wall of the cap 47 and in registration therewith. Thus as the valve 15 rises and falls due to varying induction chamber depressions, its head will decrease' or increase the number of perforations 47 exposed to induction chamber depression to vary the suction in the tubeu 9 to calibrate the suction effective to maintain a uniform .partial vacuum in the auxiliary tank and In other. respects the construction shown in Figure 3 functions and operates in a manner similar to that of the construction shown in Figure 2. .f

The invention is capable of wide variation within equivalent limits and I contemplate such variation as may beV desirable or useful in the particular adaptation of the invention shown, or in its adaptation to other similar devices. I do not restrict myself in any essential particulars, but what I claim and desire to secure by Letters Patent is:

1. In a carburetion system, the combination of a carburetor having. anl automatic air admission valve, a fuel suction device and an induction passage, an auxiliary tank disposed separate from, and below said carburetor, a suction pipe extending into said induction passage and communicating with said auxiliary tank to create .a vacuum therein, that portion of said suction pipe disposed in the induction passage being provided with a plurality of apertures in registration with i the head of said valve during the course of its travel, whereby certain of the apertures are shut olf from the induction passage as the valve' rises, a tube connecting said carburetor suction device with the lower portion of said auxiliary tank, and means for regulating the level of fuel in said auxiliary tank.

2. In a carburetion system, the combination of a carburetor having an automatic air admission valve, a fuel suction device and an induction passage, an auxiliary tank disbeing exposed to the pressure existing above l the valve when the valve is closed and some of the apertures being exposed to the pres- I sure existing below the valve when the valve rises, a tube connecting said carburetor suction device with the lower portion of said auxiliary tank, and means for regulating the levelof fuel in said auxiliary tank.

In witness whereof, I hereunto subscribe my name this 9th day of October, 1926.

ROBERT F. BRACKE.. i 

